Looks like PCRE regexps use much more CPU resources than regexp in previous zabbix versions!

We use regexps like

"some|one|other|another"

in trigger and its a trouble.
When we change the trigger expression to evaluate value 4 times by str() function, it helped, but it's a workaround and still cannot be used for all cases.

This should be investigated and addressed.

There is also suggestion to move to pcre2  in ZBXNEXT-4922, it potentially might help.